pathalongpath.py

#!/usr/bin/env python'''Copyright (C) 2006 Jean-Francois Barraud, barraud@math.univ-lille1.frThis program is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USAbarraud@math.univ-lille1.frQuick description:This script deforms an object (the pattern) along other paths (skeletons)...The first selected object is the patternthe last selected ones are the skeletons.Imagine a straight horizontal line L in the middle of the bounding box of the pattern.Consider the normal bundle of L: the collection of all the vertical lines meeting L.Consider this as the initial state of the plane; in particular, think of the patternas painted on these lines.Now move and bend L to make it fit a skeleton, and see what happens to the normals:they move and rotate, deforming the pattern.'''import inkex, cubicsuperpath, bezmisc
import pathmodifier,simpletransform
import copy, math, re, random
def flipxy(path):
for pathcomp in path:
for ctl in pathcomp:
for pt in ctl:
tmp=pt[0]
pt[0]=-pt[1]
pt[1]=-tmp
def offset(pathcomp,dx,dy):
for ctl in pathcomp:
for pt in ctl:
pt[0]+=dx
pt[1]+=dy
def stretch(pathcomp,xscale,yscale,org):
for ctl in pathcomp:
for pt in ctl:
pt[0]=org[0]+(pt[0]-org[0])*xscale
pt[1]=org[1]+(pt[1]-org[1])*yscale
def linearize(p,tolerance=0.001):
''' This function recieves a component of a 'cubicsuperpath' and returns two things: The path subdivided in many straight segments, and an array containing the length of each segment. We could work with bezier path as well, but bezier arc lengths are (re)computed for each point in the deformed object. For complex paths, this might take a while. '''
zero=0.000001
i=0
d=0
lengths=[]
while i<len(p)-1:
box = bezmisc.pointdistance(p[i ][1],p[i ][2])
box += bezmisc.pointdistance(p[i ][2],p[i+1][0])
box += bezmisc.pointdistance(p[i+1][0],p[i+1][1])
chord = bezmisc.pointdistance(p[i][1], p[i+1][1])
if (box - chord) > tolerance:
b1, b2 = bezmisc.beziersplitatt([p[i][1],p[i][2],p[i+1][0],p[i+1][1]], 0.5)
p[i ][2][0],p[i ][2][1]=b1[1]
p[i+1][0][0],p[i+1][0][1]=b2[2]
p.insert(i+1,[[b1[2][0],b1[2][1]],[b1[3][0],b1[3][1]],[b2[1][0],b2[1][1]]])
else:
d=(box+chord)/2
lengths.append(d)
i+=1
new=[p[i][1] for i in range(0,len(p)-1) if lengths[i]>zero]
new.append(p[-1][1])
lengths=[l for l in lengths if l>zero]
return(new,lengths)
class PathAlongPath(pathmodifier.Diffeo):
def __init__(self):
pathmodifier.Diffeo.__init__(self)
self.OptionParser.add_option("--title")
self.OptionParser.add_option("-n", "--noffset",
action="store", type="float",
dest="noffset", default=0.0, help="normal offset")
self.OptionParser.add_option("-t", "--toffset",
action="store", type="float",
dest="toffset", default=0.0, help="tangential offset")
self.OptionParser.add_option("-k", "--kind",
action="store", type="string",
dest="kind", default=True,
help="choose between wave or snake effect")
self.OptionParser.add_option("-c", "--copymode",
action="store", type="string",
dest="copymode", default=True,
help="repeat the path to fit deformer's length")
self.OptionParser.add_option("-p", "--space",
action="store", type="float",
dest="space", default=0.0)
self.OptionParser.add_option("-v", "--vertical",
action="store", type="inkbool",
dest="vertical", default=False,
help="reference path is vertical")
self.OptionParser.add_option("-d", "--duplicate",
action="store", type="inkbool",
dest="duplicate", default=False,
help="duplicate pattern before deformation")
def prepareSelectionList(self):
idList=self.options.ids
idList=pathmodifier.zSort(self.document.getroot(),idList)
id = idList[-1]
self.patterns={id:self.selected[id]}
## ##first selected->pattern, all but first selected-> skeletons## id = self.options.ids[-1]## self.patterns={id:self.selected[id]}if self.options.duplicate:
self.patterns=self.duplicateNodes(self.patterns)
self.expandGroupsUnlinkClones(self.patterns, True, True)
self.objectsToPaths(self.patterns)
del self.selected[id]
self.skeletons=self.selected
self.expandGroupsUnlinkClones(self.skeletons, True, False)
self.objectsToPaths(self.skeletons)
def lengthtotime(self,l):
''' Recieves an arc length l, and returns the index of the segment in self.skelcomp containing the coresponding point, to gether with the position of the point on this segment. If the deformer is closed, do computations modulo the toal length. '''if self.skelcompIsClosed:
l=l % sum(self.lengths)
if l<=0:
return 0,l/self.lengths[0]
i=0
while (i<len(self.lengths)) and (self.lengths[i]<=l):
l-=self.lengths[i]
i+=1
t=l/self.lengths[min(i,len(self.lengths)-1)]
return i, t
def applyDiffeo(self,bpt,vects=()):
''' The kernel of this stuff: bpt is a base point and for v in vectors, v'=v-p is a tangent vector at bpt. '''
s=bpt[0]-self.skelcomp[0][0]
i,t=self.lengthtotime(s)
if i==len(self.skelcomp)-1:
x,y=bezmisc.tpoint(self.skelcomp[i-1],self.skelcomp[i],1+t)
dx=(self.skelcomp[i][0]-self.skelcomp[i-1][0])/self.lengths[-1]
dy=(self.skelcomp[i][1]-self.skelcomp[i-1][1])/self.lengths[-1]
else:
x,y=bezmisc.tpoint(self.skelcomp[i],self.skelcomp[i+1],t)
dx=(self.skelcomp[i+1][0]-self.skelcomp[i][0])/self.lengths[i]
dy=(self.skelcomp[i+1][1]-self.skelcomp[i][1])/self.lengths[i]
vx=0
vy=bpt[1]-self.skelcomp[0][1]
if self.options.wave:
bpt[0]=x+vx*dx
bpt[1]=y+vy+vx*dy
else:
bpt[0]=x+vx*dx-vy*dy
bpt[1]=y+vx*dy+vy*dx
for v in vects:
vx=v[0]-self.skelcomp[0][0]-s
vy=v[1]-self.skelcomp[0][1]
if self.options.wave:
v[0]=x+vx*dx
v[1]=y+vy+vx*dy
else:
v[0]=x+vx*dx-vy*dy
v[1]=y+vx*dy+vy*dx
def effect(self):
if len(self.options.ids)<2:
inkex.debug("This extension requires that you select two paths.")
return
self.prepareSelectionList()
self.options.wave = (self.options.kind=="Ribbon")
if self.options.copymode=="Single":
self.options.repeat =False
self.options.stretch=Falseelif self.options.copymode=="Repeated":
self.options.repeat =True
self.options.stretch=Falseelif self.options.copymode=="Single, stretched":
self.options.repeat =False
self.options.stretch=Trueelif self.options.copymode=="Repeated, stretched":
self.options.repeat =True
self.options.stretch=True
bbox=simpletransform.computeBBox(self.patterns.values())
if self.options.vertical:
#flipxy(bbox)...
bbox=(-bbox[3],-bbox[2],-bbox[1],-bbox[0])
width=bbox[1]-bbox[0]
dx=width+self.options.space
for id, node in self.patterns.iteritems():
if node.tag == inkex.addNS('path','svg') or node.tag=='path':
d = node.get('d')
p0 = cubicsuperpath.parsePath(d)
if self.options.vertical:
flipxy(p0)
newp=[]
for skelnode in self.skeletons.itervalues():
self.curSekeleton=cubicsuperpath.parsePath(skelnode.get('d'))
if self.options.vertical:
flipxy(self.curSekeleton)
for comp in self.curSekeleton:
p=copy.deepcopy(p0)
self.skelcomp,self.lengths=linearize(comp)
#!!!!>----> TODO: really test if path is closed! end point==start point is not enough!
self.skelcompIsClosed = (self.skelcomp[0]==self.skelcomp[-1])
length=sum(self.lengths)
xoffset=self.skelcomp[0][0]-bbox[0]+self.options.toffset
yoffset=self.skelcomp[0][1]-(bbox[2]+bbox[3])/2-self.options.noffset
if self.options.repeat:
NbCopies=max(1,int(round((length+self.options.space)/dx)))
width=dx*NbCopies
ifnot self.skelcompIsClosed:
width-=self.options.space
bbox=bbox[0],bbox[0]+width, bbox[2],bbox[3]
new=[]
for sub in p:
for i in range(0,NbCopies,1):
new.append(copy.deepcopy(sub))
offset(sub,dx,0)
p=new
for sub in p:
offset(sub,xoffset,yoffset)
if self.options.stretch:
for sub in p:
stretch(sub,length/width,1,self.skelcomp[0])
for sub in p:
for ctlpt in sub:
self.applyDiffeo(ctlpt[1],(ctlpt[0],ctlpt[2]))
if self.options.vertical:
flipxy(p)
newp+=p
node.set('d', cubicsuperpath.formatPath(newp))
e = PathAlongPath()
e.affect()